Low-temperature solid oxide fuel cells with a La0.8Sr0.2MnO3 (LSM) interlayer between the Ce0.9Gd0.1O1.95 (GDC) electrolyte membrane (20 mu m) and the Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF)-GDC composite cathode are fabricated by sintering the BSCF-GDC composite cathodes at 900,950 and 1000 degrees C. The results of scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) fora model LSM/BSCF bi-layer pellet suggest that Ba, Co and Fe in BSCF as well as La and Mn in LSM have diffused into their counter sides. The X-ray diffraction (XRD) results on the simulated cells also indicate the incorporation of La into the CDC electrolyte membrane and the mutual diffusion of elements between the LSM layer and the BSCF layer. Analysis of the impedance spectra and interfacial reaction activation energies shows that LSM interlayer accelerates the oxygen reduction. Considering a good cell performance and the highest open-circuit voltages (OCVs) at 600-500 degrees C, the optimum sintering temperature of BSCF-GDC composite cathode onto LSM interlayer is 900 degrees C. (C) 2008 Elsevier B.V. All rights reserved.